title: Peptide-bridged assembly of hybrid nanomaterial and its application for caspase-3 detection.
abstract: Recent developments in the rational design and the controlled assembly of nanoscale building blocks have resulted in functional devices such as nano-optoelectronics, novel contrast probes for molecular imaging, and nanosensors. In the present study, we designed and synthesized a hybrid nanomaterial consisting of [Ru(bpy)3](2+)-encapsulated silica nanoparticles (SiNPs) and gold nanoparticles (AuNPs) through peptide-bridged assembly in a controllable way. A peptide that contains recognition sequence DEVD specific for active caspase-3 cleavage was employed to bring SiNPs and AuNPs into close proximity through specific molecular recognition. A FRET system with SiNPs as energy donors and AuNPs as energy acceptors has been thus developed and applied for caspase-3 detection. A change in distance between the two building blocks resulted in a change in FRET efficiency, causing a ratiometric change in emission. Caspase-3 triggers the cleavage of the peptide links between the two nanoparticles and releases AuNPs from the nanohybrids, inducing the activation of SiNPs to the "ON" state. The fluorescence turn-on response is specific to caspase-3 and allows the detection of caspase-3 as low as 0.05 U mL(-1) (∼6 pM).
authors.affiliation: Key Laboratory of Sensing Technology and Biomedical Instruments (Guangdong Province), School of Engineering, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Yupeng
authors.initials: Y
authors.lastname: Shi
authors.forename: Changqing
authors.initials: C
authors.lastname: Yi
authors.forename: Zhaomin
authors.initials: Z
authors.lastname: Zhang
authors.forename: Heng
authors.initials: H
authors.lastname: Zhang
authors.forename: Meijin
authors.initials: M
authors.lastname: Li
authors.forename: Mengsu
authors.initials: M
authors.lastname: Yang
authors.forename: Qing
authors.initials: Q
authors.lastname: Jiang
mesh_terms: D053148:Caspase 3 / Q000032:analysis* / Q000378:metabolism; D031541:Fluorescence Resonance Energy Transfer; D006046:Gold / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry; D049329:Nanostructures / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry
chemical_list: D009942:Organometallic Compounds; D010455:Peptides; C415768:tris(2,2'-bipyridyl)ruthenium(II); D006046:Gold; D012822:Silicon Dioxide; D053148:Caspase 3